I am trying to "optimize" a screen printing operation. This operation screens solder-paste for both SMD and Through-Hole(Paste-In-Hole). I am using a solder-paste that is 90% solids(Non-No-Clean) with a viscosity of 1M(cps)+-100K(cps). Whew!...Finally my question(s): I have found that a higher viscosity helps when doing fine-pitch but I may be hurting myself when doing Paste-In-Hole. Is there a relationship (weak or strong) between solids-content and viscosity or do I keep the solids-content a constant and simply ask for a lower viscosity solder-paste if I need it for (PIH)? Thanks Harlan [log in to unmask]